On Thu, Dec 29, 2022 at 01:47:49PM +0100, Borislav Petkov wrote: > On Wed, Dec 28, 2022 at 11:31:34PM -0800, H. Peter Anvin wrote: > > As far as a crash... that sounds like a big and a pretty serious one at > > that. > > > > Could you let me know what kernel you are using and how *exactly* you are > > booting it? > > Right, with CONFIG_X86_VERBOSE_BOOTUP=y in a guest here, it says: > > early console in extract_kernel > input_data: 0x000000000be073a8 > input_len: 0x00000000008cfc43 > output: 0x0000000001000000 > output_len: 0x000000000b600a98 > kernel_total_size: 0x000000000ac26000 > needed_size: 0x000000000b800000 > trampoline_32bit: 0x000000000009d000 > > so that's a ~9M kernel which gets decompressed at 0x1000000 and the > output len is, what, ~180M which looks like plenty to me...
I think you might have misunderstood the thread. First, to reproduce the bug that this patch fixes, you need a kernel with a compressed size of around 16 megs, not 9. Secondly, that crash is well understood and doesn't need to be reproduced; this patch fixes it. Rather, the question now is how to improve this patch to remove the 62 meg limit. I'll follow up with hpa's request for reproduction info. Jason
